The invention is directed to a process for the production of 2-isocyanato-2,3-dehydrocarboxylic acid esters (1-alkoxycarbonyl-1-alkenyl-isocyanates) of the general formula: ##STR3## in which
R.sup.1 is a straight chain or branched C.sub.1 -C.sub.4 -alkyl group (e.g., methyl, ethyl, propyl, isopropyl, butyl, sec. butyl, t-butyl), a phenyl group or a benzyl group,
R.sup.2 is hydrogen or a methyl group, and
R.sup.3 is hydrogen, a straight or branched C.sub.1 -C.sub.16 -alkyl group (e.g., methyl, ethyl, propyl, isopropyl, butyl, t-butyl, hexyl, octyl, decyl, hexadecyl), a C.sub.3 -C.sub.8 -cycloalkyl group (e.g., cyclopropyl, cyclopentyl, cyclohexyl, cyclooctyl), a C.sub.1 -C.sub.6 -alkylmercapto group (e.g., methylmercapto, ethylmercapto, propylmercapto, isopropylmercapto, butylmercapto, hexylmercapto), or a phenyl group.
There is known from European Pat. No. 86424 a process for the production of 1-alkenyl-isocyanates which contain no additional functional groups. This process which comprises a dehydrohalogenation step to form the C.dbd.C double bond, however, is not suited for the production of compounds of general formula (I).